Mechanical pencil



Nov. 16 1926.

J. c. WAHL MECHANICAL PENCIL Filed Nov. 24. 1923 I'I I1 I. III. I n! I11. I. l I, I

WWMMMMMMW PimmE AI lllll l I Patented Nov. 16, 1926.

UNITED, STATES PATENT OFFICE.

JOHN cQwant, or onrcaeo, rumors, assmnon 'ro THE WAI-IL couranmor cmcaeo, rumors, a; conronarron or DELAWARE.

amcnamcn. rENcI Application filed November 24. 1923. Serial No. 676,703.

This invention relates to improvements in mechanical pencils of the type in which the lead is pro elled through a ribbed tip which supports t ie lead and prevents it from rotating in the pencil. In passing through the tip the ribs therein cut into the lead and pro-.

Figure 1 is a View, artially in longitu' dinal section and partia ly in elevation, of a mechanical pencil with the tip according to the present invention attached thereto.

Figure 2 is a view in longitudinal section of the improved tip and co-related parts. a

Figure 3 is a view taken on the line 3-3 M of Figure 2 looking in the direction of thearrows.

Figure 4 is a view of the tip according to this invention, showing the same perspective detached from the other parts of the pencil.

Figure dis a sectional view on an enlarged scale of the end of the tip with no lead therein. I

In the drawings numeral 1 indicates an outer barrel of a mechanical pencil tapered at one end to form a seat for atip 2. Numeral 3 indicates a threaded inner sleeve which is swedged at one end to form a lead guide 4 to which the tip is adapted to be attached through the means of threaded engagement.

The lead propelling mechanism 5 is mounted within the tube 3. and the cross head 6 cooperates with the interior threads on the tube 3 to propel a lead 7 through the tip. The tip 2 has a passageway 8 therein,

threaded at its uppermost extremity as at 9 to engage the external threads on the lower end of the lead guide 4.

The aperture in the lower andsmaller end of the tip 2 is milled in a generally triangular shape, as is illustrated in Figure 3, and ribs 10 are formed on the flat sides of the triangle. These ribs 10 project into theap- ,erture of the tip and act to bite 'into the lead 7 as it is forced into the tip 2 by the propelling mechanism, thus preventing the the end of the tip 2, thus preventing this dust from gathering around and above the ribs 10, and packing firmly in the tip 2 and finally clogging up the tip.

Havingidescribed my invention, what I claim as new and desire tosecure by Letters Patent is:

1. Ina mechanical pencil, a tip having a bore't'herein for the passage of a lead, ribs in said bore adapted to cut into said lead,

the surface of said bore between said ribs being separated from the lead to provide lougitudinal spaces alongsideof the lead and extending to the end of the tip to permit the escape from the tip of the dust cut from the lead by said ribs.

2. In a mechanical pencil. a tip having a bore therein for the passage of a circular lead, ribs in said bore adapted to cut into said lead, said bore being at its lowermost end of general triangular form whereby the surface of said bore between said ribs is separated from the lead to provide spaces alon side the lead to permit the escape from the tip of the dust cut fromthe leadby said ribs. 1

4 In witness whereof, I have hereuutosub- 

